Dr Murphy is investigating the effect of caffeine on students' performance on a memory task. She randomly allocates 200 university students into three groups. Thirty minutes before the task, she asks Group A to drink 30ml of black coffee, Group B to drink 50ml and Group C to drink 100ml. Group B is:

Question

Quizplus · Accepted Answer

Group B is receiving a different quantity of the independent variable (caffeine) compared to Groups A and C. This variation is quantitative, as it's based on the amount of black coffee they are drinking. Therefore, Group B is the condition that varies quantitatively from the others. A control group would not receive any caffeine, and an experimental group would receive a different treatment altogether, such as a placebo or a different substance instead of caffeine. A qualitative variation would involve a different type of treatment, such as giving one group caffeine pills and another group caffeine gum.

Dr Murphy Is Investigating the Effect of Caffeine on Students